fix styles on the add card page, move the parser to a separate file, change the styles of the page of one news item, add a parser for the subscription page, add the input field for the qr code

lib/domain/entities/subscription.dart

@@ -6,6 +6,7 @@ class Subscription {
   final String title;
   final String shortDescription;
   final String fullDescription;
+  final String fullDescriptionJson;
   final int planId;
   final bool isActive;
   final bool isCurrent;
@@ -22,6 +23,7 @@ class Subscription {
     required this.title,
     required this.shortDescription,
     required this.fullDescription,
+    required this.fullDescriptionJson,
     required this.planId,
     required this.isActive,
     required this.currency,
@@ -43,6 +45,7 @@ class Subscription {
       title: json['title'] ?? '',
       shortDescription: json['shortDescription'] ?? '',
       fullDescription: json['fullDescription'] ?? '',
+      fullDescriptionJson: json['fullDescriptionJson'] ?? '',
       planId: json['planId'] ?? 0,
       isActive: json['isActive'] ?? false,
       currency: currencyData['currency'] ?? 'BYN',